Coffee maker



Nov. 7, 1933. w JENKINS v 1,934,070

V COFFEE MAKER Filed Nov. 17,- 1932 INVENTOR.

BY W W$ ATTORNEYS 1 00/ WJan/whs.

Patented Nov. 7, 1933 UNITED STATES PATENT OFFICE COFFEE MAKER Application November 17, 1932 Serial No. 643,039

Claims.

My invention relates to coffee makers, and-particularly to coifee makers of the so-calledvacuum type in which liquid is caused tofiow automatically by pressure or vacuum from one con- 5 tainer to another.

The subject matter of the presentapplication is closely related to and is a modification of that of the copending application of Raymond W. Kell and Charles D. Barth, Serial No. 643,060, filed November 17, 1932.

It has been proposed heretofore to provide coffee makers of the same general type as that of the present invention, but the devices of the prior art have had certain disadvantages that are avoided in the coffee maker of my invention. For example, certain coffee makers that. have been proposed have required the employment of straining devices of fabric that must be replaced at frequent intervals, and which when used must be either discarded or washed and dried between successive uses thereof.

Other coffee makers have included metal parts with which the liquid coffee is in contact while at a relatively high temperature. The coffee reacts chemically with the metal surfaces of such parts, and the result is to impart a taste or flavor to the coffee that is foreign to the natural taste of coffee. In addition, the salts produced by such chemical reactions may be somewhat dis agreeable or possibly even slightly harmful in the case of certain metals, such as brass or copper.

In accordance with the present invention I provide a coffee maker all of the interior parts of which are non-metallic and preferably of glass or other suitable ceramic or refractory material that is inert with respect to the chemical constituents of coffee, and which does not impart an unnatural taste thereto. Furthermore, the

coffee maker of my invention comprises such relatively few and simple parts that uniformly excellent coffee may be made even by those of little skill in the art of making coffee. Also, the construction of the coffee maker is such that it may be easily and conveniently assembled and disassembled for cleaning or sterilizing of the surfaces in contact with the coffee.

An important feature of my coffee maker is the provision of a spherical member of glass which serves as a valve or closure to permit flow of water from one container to the other, but which acts as a filter or strainer to prevent the passage of sediment or grounds that-may be contained in the liquid coffee when the latter flows in the opposite direction. This valve member or strainer in connection with the accompanying drawing, in

which the single figure is a view in central vertical section of my improved coffee maker.

Referring to the drawing, the coffee maker of my invention comprises a lower container 1, an upper container 2 having an integral tube 3 extending vertically into the lower container 1, a valve or strainer 4 for the tube 3, and a handle 5 for the lower container 1.

The lower container 1, which is preferably of glass, is provided at its top with a relatively small neck portion 6, the upper portion of which flares outwardly, whereby the container may be conveniently filled with water, or coffee may be poured therefrom.

The upper container 2 is also preferably of glass, and it may be open at its top. The tube 3 is provided adjacent to its upper end with a sleeve or gasket 7 that is of rubber or other suitable flexible or resilient material, and which, when inserted within the neck portion 6 of the lower container, hermetically seals the connection between the containers 1 and 2. The tube 3 ends a short distance above the bottom of the lower container 1, this distance regulating the level of the water remaining in the lower con-. tainer during the operation of the coffee maker.

The strainer 4, which is of glass and of spherical shape, and which may be an ordinary marble, constitutes a valve for the opening through the tube 3. The curved surface of the strainer 4 rests upon a slightly enlarged portion 8 of the tube 3, and is permanently and loosely retained in its position by projections or nibs 9 integral with the tube 3, and which extend inwardly. The nibs 9 are formed after the strainer 4 is in position by heating the tube 3 to a somewhat plastic state.

This arrangement provides that the strainer 4 may, if necessary, move upwardly against the force of gravity to permit the upward flow of liquid through the tube 3. The bottom surfaces of the strainer 4, even if of smooth glass, have a slightly imperfect fit with the adjacent walls of the container 2, and accordingly liquid may be drawn downwardly between these surfaces at a relatively slow rate, as will be later described. However, in order to insure that there will not be a perfectly fluid-tight fit between these surfaces, the strainer 4 may, if desired, be provided with a slightly rough surface, which may be secured by the addition of fine sand or fine glass particles while the strainer 4 is hot and in a slightly plastic state, and then applying a flame thereto for a brief period. An equivalent effect may be secured by forming the strainer 4 in a mold adapted to provide a surface that is stippled or slightly irregular.

The neck portion 6 of the lower container 1 is provided with a sleeve 12 that is of rubber or other suitable resilient and heat-insulating material, and which is gripped by a hinged clamping ring 13 of the handle 5, which may be of metal if desired, since it is not in contact with the coffee.

In the operation of the improved coffee maker, it may be assumed that the upper container 2 is separated from the lower container 1, and that the latter has been filled with water to a suitable level. It will be understood that the quantity of water will correspond approximately to that of the coffee that is desired to be made. The upper container, having the strainer 4 in place, and with its sleeve '7, is then placed in sealing position on the lower container 1, as illustrated, and suificient ground coffee is placed in the upper container 2 to make the beverage of the desired strength.

The lower container is then suitably heated, as by gas or electricity, as desired, and when the water contained therein reaches the boiling point steam will be formed which will collect above the surface of the water, and the pressure in the lower container will gradually increase. As the boiling continues and the pressure increases, water will be forced upwardly through the tube 3 and around the strainer 4 into the upper container.

If the water is heated gradually the strainer 4 will not be lifted appreciably, but if the heating is rapid the strainer 4 may be lifted to permit the water to flow at a rate corresponding to that of the generation of steam in the lower container. This flow continues until the level of the water in the lower container falls to the bottom'of the tube 3.

, The hot water which is now in the upper container 2 causes an infusion of the colfee therein. The liquid remains in the upper container as long as sufficient heat is applied to the bottom of the lower container to maintain the pressure required. In addition, continued boiling of the water in the lower container will force steam upwardly through tube 3, and it will escape to the atmosphere through the liquid in the upper container. This process may continue for any desired time, but preferably not more than from three to five minutes.

At the end of the desired period heating of the water in the container below is discontinued. The strainer 4, in case it has been lifted, then drops to its illustrated position.

The stream above the surface of the .water in the lower'container now gradually condenses as the temperature falls with a corresponding lowering of pressure therein, and when the steam is sufficiently condensed, the vacuum thus produced causes the water in the upper container to be forced downwardly through the extremely narrow crevices between the strainer 4 and the walls of the upper container 2, whereby the liquid coffee flows through at a relatively slow rate and the a sediment or grounds of the coffee are retained in the upper container because the extremely slight openings are not sumcient to permit them to flow past the strainer.

The downward flow. continues until all of the liquid is transferred to the lower container,

whereupon the upper container may be removed. The liquid coffee which is now in the lower container may be served from the latter by using the handle 5 to lift or tilt the lower container, as

desired.

Inasmuch as all of the parts of the coffee maker with which the liquid coffee comes in contact are of glass which is inert to the chemical constituents of coffee, there can be no foreign taste such as that caused by contact of hot liquid coffee with metal surfaces. The {operation of the coffee maker is extremely simple and entirely automatic when heat is applied thereto and is discontinued. The process is continued until certain desirable constituents of the cofiee have been infused into the liquid, and the beverage thus produced has the natural taste of coffee.

While the apparatus of the present invention has been described with particular reference to coffee, it is also peculiarly adapted to the making of tea, since the liquid in the upper container is always below the boiling point. It is well known that in making tea boiling water should not be in contact with the tea leaves.

The apparatus is also adapted for making infusions of various kinds, such as chemical or pharmaceutical preparations, as will be readily understood.

The apparatus contains only one movable part, and that need not be removed for cleaning or sterilizing of the parts in contact with the coffee.

These and various other advantages will be appreciated by those skilled in the art of manu-' facturing and operating coffee makers.

I claim:

1. Apparatus for making infusions of coffee, tea or the like,comprising a lower container and an upper container having a tube connected to and extending into said lower container and through which liquid flows from the lower container to the upper container or vice versa, and a substantially spherical closure member for the bore of said tube which permits relatively rapid flow of liquid upwardly through said tube but which serves as a strainer when liquid flows downwardly therein.

2. Apparatus for making infusions of coffee, tea or the like, comprising a lower container and an upper container having a tube connected to and extending into said lower container, and a closure member of substantially spherical shape at an upper portion of said tube and movable upwardly to permit liquid to flow upwardly through the latter and operable in its closed position to permit downward flow at a relatively slow rate and to serve as a strainer by reason of the slight clearance between the closure member and the seat therefor.

3. Apparatus for making infusions of coffee, tea or the like, comprising a lower container and an upper container having a tube connected to and extending into said lower container, and a closure member of substantially spherical shape at an upper portion of said tube and loosely mounted for free rotative movement but limited lateral movement for permitting upward flow of liquid therearound, said closure member having a slightly imperfect fit upon its seat whereby it operates as a strainer to permit slow downward flow of liquid while preventing passage of sediment.

4. Apparatus for making infusions of coffee, tea or the like, comprising a lower container and an upper container having a tube connected to and extending into said lower container, a closure member of substantially spherical shape at an tegral therewith a tube extending into the lower container and connected thereto, a substantially spherical closure member of glass for the opening through the tube for permitting relatively free upward flow of liquid through the tubular member but restricting downward flow therethrough, and projections integral with said upper contain er for retaining the spherical closure member adjacent its closed position.

PAUL W. JENKINS. 

